414 
SYMPOSIUM PHOTO INTERPRETATION, DELFT 1962 
Fig. 2. “Celtic” fields, Shillingstone Hill, Dorset. The evidence for secondary strip ploughing 
is clear, particularly right of X. now mostly ploughed down. Distance X-Y about 360 metres. 
(Near-vertical air photograph reproduced by permission of the British Air Ministery, British 
Crown Copyright reserved) 
land remains as peripheral and of little count in the Iron Age and Romano- 
British periods. The downs were teeming with well-ordered settlements as well 
as fields. 
The search also involves at least an initial analysis, which is the second 
operation mentioned. The importance of air photographs here simply cannot 
be over-estimated. For instance, settlements, tracks and other earthworks which 
may be significantly earlier or later than the fields are quickly recognised or 
perhaps, just as important, suspected and ear-marked for further investigation. 
But it is evidence for the subtle alterations of later ploughing in or over “Celtic” 
fields which air photographs best and most quickly display. By so doing they 
show that we have to look on the history of our fields - and downland - as one 
of development, not status. We have to consider development within the “Cel 
tic” field phase and after. In this latter case a most interesting and so far little- 
investigated aspect of English economic history is brought to light. This is the 
apparent medieval cultivation in an open-field system of large tracts of downland 
hitherto widely regarded as untouched since the Roman period. Excavation 
in such an area, on Fyfield Down, Wiltshire, by P. J. Fowler, has proved the 
existence of a long-house and other buildings of 11 th— 13th century A.D. in a